F4U-1A part 2: an experiment with soldering

The seat on a real Corsair was basically just a metal bucket. The pilot sat on his parachute for a “cushion.” So it follows that photo etched brass would make the basis for a reasonable facsimile. I have the kit seat, of course, and an Ultracast resin, but let’s see how the seat from the Eduard PE set builds out, while trying a new (to me) technique at the same time.

materials: iron, flux, solder, extra hands, and something to solder.

I’ve done a bit of electronics soldering, but this is my first go with a scale model component. I was a little intimidated by trying to solder precisely enough for modeling, but I did a couple experiments (and have a backup plan) so decided to give it a go. 

First we need to cut out and form the part. A quick remedial for those who are new to this (looking in the mirror, here). A firm surface—acetate, in this case—and a curved blade help us from deforming the part while cutting. 

After cutting, flat pliers help hold the part in place while filing off the fret stubs with a fine file.

A photo etch bending tool can help make precise bends with small parts. This is The BUG (not sure why it’s all caps, but that’s what they call it) but they all seem to work similarly. I got it because it was the cheapest all metal design I could find. 

This chair is pretty simple, so it’s not as critical here, but it’s still a help. Slip the part to be folded in an appropriate cut out, lock down, and then slide a razor blade under and gently fold up. Easy peasy.

Do the other side the same way. (With complex shapes, think through the folds first, so you don’t fold yourself into a corner.)

And finally fold up the seat by hand. The seat needs a curve formed into the end to match the curve of the sides. I used a dowel as a guide. In the process I broke off the bottom. It’s not a big deal, but makes the first soldering step a bit trickier.

The principal is simple enough: heat the pieces to be joined enough that they melt the solder, creating a “welded” (nerd alert: what’s actually happening is ‘intermetallic bonding’) joint. Don’t try to melt the solder directly with the iron, because unless the parts being joined are hot enough, the solder won’t dissolve in the base and there won’t be a strong join. 

There’s a bunch of ways this could go sideways, and I’m sure I’ll find most of them. 

First, dab on a bit of flux where you want the solder to flow. The solder I’m using happens to be rosin core, which is usually enough for electronics work, but we can’t depend on that to guide the solder for this. 

The solder escaped a bit. Bugger! But I can sand this down and it will be fine. I couldn’t get the parts aligned with the helping hands, so the seat bottom rests on the second hand, and then I’m pushing it into place with a toothpick and a bit a blue tack. (You’d think the blue tack would melt, but it doesn’t seem to.)

Continue with the sides, and soon enough, voila…  a seat!  The nice thing about solder is that it’s file and sandable, or you can carve it. You don’t want to leave giant globs, but if it’s a bit messy you can clean it up. I still have to add the cross panel, but my Jedi soldering skills aren’t quite there yet for super fine work, so I’m going to attach with CA.

L to R: kit seat, the brass seat, and the Ultracast. 

The kit seat is out. It looks like an industrial barkalounger. 

This isn’t a great shot of the Ultracast, but I’m not totally feeling it yet. The detail feels a bit mushy. That top bar (omitted from the kit, and needs to be addressed regardless) is a bit droopy, which doesn’t give much confidence in protecting poor Captain Stub on his mission (and if he doesn’t come back, that would change the whole corse of history, making my eventual appearance much less likely!). 

I haven’t completely decided, but I’m leaning toward the Eduard at the moment. There’s a slight misalignment on the cross panel—riding a touch high on the left, operator error—but I’m pretty sure I can hide that with an artfully placed seatbelt.

One interesting thing to note: the kit seat is 16 scale inches wide, the Ultracast 17”, and the Eduard 18”. Later, I gently squeezed the brass, slightly increasing the radius in the seat back and got it down to 17 scale inches. Does anyone know what the width of a standard US aircraft bucket seat actually was?

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